Hello Trond Myklebust,
The patch 57bfa89171e5: "NFSv4: Deal more correctly with duplicate
delegations" from Jan 25, 2008, leads to the following static checker
warning:
fs/nfs/delegation.c:482 nfs_inode_set_delegation()
warn: missing error code here? 'nfs_detach_delegation_locked()' failed. 'status' = '0'
fs/nfs/delegation.c
421 int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
422 fmode_t type,
423 const nfs4_stateid *stateid,
424 unsigned long pagemod_limit)
425 {
426 struct nfs_server *server = NFS_SERVER(inode);
427 struct nfs_client *clp = server->nfs_client;
428 struct nfs_inode *nfsi = NFS_I(inode);
429 struct nfs_delegation *delegation, *old_delegation;
430 struct nfs_delegation *freeme = NULL;
431 int status = 0;
^^^^^^^^^^
"status" is always success.
432
433 delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
434 if (delegation == NULL)
435 return -ENOMEM;
436 nfs4_stateid_copy(&delegation->stateid, stateid);
437 refcount_set(&delegation->refcount, 1);
438 delegation->type = type;
439 delegation->pagemod_limit = pagemod_limit;
440 delegation->change_attr = inode_peek_iversion_raw(inode);
441 delegation->cred = get_cred(cred);
442 delegation->inode = inode;
443 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
444 spin_lock_init(&delegation->lock);
445
446 spin_lock(&clp->cl_lock);
447 old_delegation = rcu_dereference_protected(nfsi->delegation,
448 lockdep_is_held(&clp->cl_lock));
449 if (old_delegation == NULL)
450 goto add_new;
451 /* Is this an update of the existing delegation? */
452 if (nfs4_stateid_match_other(&old_delegation->stateid,
453 &delegation->stateid)) {
454 spin_lock(&old_delegation->lock);
455 nfs_update_inplace_delegation(old_delegation,
456 delegation);
457 spin_unlock(&old_delegation->lock);
458 goto out;
I think these used to return -EIO back in the day.
459 }
460 if (!test_bit(NFS_DELEGATION_REVOKED, &old_delegation->flags)) {
461 /*
462 * Deal with broken servers that hand out two
463 * delegations for the same file.
464 * Allow for upgrades to a WRITE delegation, but
465 * nothing else.
466 */
467 dfprintk(FILE, "%s: server %s handed out "
468 "a duplicate delegation!\n",
469 __func__, clp->cl_hostname);
470 if (delegation->type == old_delegation->type ||
471 !(delegation->type & FMODE_WRITE)) {
472 freeme = delegation;
473 delegation = NULL;
474 goto out;
475 }
476 if (test_and_set_bit(NFS_DELEGATION_RETURNING,
477 &old_delegation->flags))
478 goto out;
479 }
480 freeme = nfs_detach_delegation_locked(nfsi, old_delegation, clp);
481 if (freeme == NULL)
482 goto out;
status isn't set
483 add_new:
484 list_add_tail_rcu(&delegation->super_list, &server->delegations);
485 rcu_assign_pointer(nfsi->delegation, delegation);
486 delegation = NULL;
487
488 atomic_long_inc(&nfs_active_delegations);
489
490 trace_nfs4_set_delegation(inode, type);
491
492 spin_lock(&inode->i_lock);
493 if (NFS_I(inode)->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ATIME))
494 NFS_I(inode)->cache_validity |= NFS_INO_REVAL_FORCED;
495 spin_unlock(&inode->i_lock);
496 out:
497 spin_unlock(&clp->cl_lock);
498 if (delegation != NULL)
499 __nfs_free_delegation(delegation);
500 if (freeme != NULL) {
501 nfs_do_return_delegation(inode, freeme, 0);
502 nfs_free_delegation(freeme);
503 }
504 return status;
505 }
regards,
dan carpenter
